68 barracuda tire size question

BFG, Michelin, and Goodyear do not support a 215/75-14 tire on their websites, so I do not have their data available. What I found was that a 215/70-14 tire is the widest T/A radial that they recommend for a 5½" wide rim. They recommend a minimum of a 6" rim for a 225/70-14.

Will a 225/70 fit on a 5½" rim? Physically, yes. Functionally, no. The bead will be pinched in at the top. This tends to lift the tire at the outer edges, reducing the anticipated gain in tread width.